CVE-2016-20035
Wowza Streaming Engine 4.
Executive Summary
CVE-2016-20035 is a medium severity vulnerability affecting appsec, ai-code, pii-secrets. It is classified as CSRF. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"This critical flaw stems from within Wowza Streaming Engine 4.5.0, allowing an architectural oversight in input validation. If successfully exploited, a malicious user could inject malicious logic that alters the execution flow of the application engine. Precogs AI Analysis Engine leverages inter-procedural taint tracking to harden the environment against lateral movement."
What is this vulnerability?
CVE-2016-20035 is categorized as a critical Cross-Site Scripting (XSS) flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
Wowza Streaming Engine 4.5.0 contains a cross-site request forgery vulnerability that allows attackers to perform administrative actions by crafting malici...
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 5.3 (MEDIUM) |
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| Published | March 16, 2026 |
| Last Modified | March 19, 2026 |
| Related CWEs | CWE-352 |
Impact on Systems
✅ Session Hijacking: Attackers can steal active user session tokens (cookies) to impersonate the victim.
✅ Phishing Execution: Malicious scripts can dynamically alter DOM content to present fraudulent login forms.
✅ Worm Propagation: Stored XSS can spread autonomously as users visit the infected page.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Output Encoding Implement strict context-aware output encoding (HTML, JavaScript, Attribute, CSS) before rendering user data.
2. Content Security Policy (CSP) Deploy a rigorous CSP header to restrict script execution exclusively to trusted domains.
3. Framework Defenses Utilize native UI framework protections (e.g., React DOM escaping) and avoid dangerouslySetInnerHTML.
Vulnerability Signature
// Example DOM-based XSS vulnerability
const user_input = new URLSearchParams(window.location.search).get('q');
// VULNERABLE: Direct insertion into innerHTML
document.getElementById('results').innerHTML = "Results for: " + user_input;
// EXPLOIT PAYLOAD: ?q=\<img src=x onerror=alert(document.cookie)\>
References and Sources
- NVD — CVE-2016-20035
- MITRE — CVE-2016-20035
- CWE-352 — MITRE CWE
- CWE-352 Details
- Application Security Vulnerabilities
- AI Code Security Vulnerabilities
- PII and Secrets Exposure
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Malicious third-party website |
| Vector | Cross-site request leveraging authenticated session cookies |
| Sink | State-changing server endpoint without CSRF protection |
| Impact | Unauthorized actions performed on behalf of the victim (e.g., password change, fund transfer) |
Vulnerable Code Pattern
// ❌ VULNERABLE: Missing CSRF token validation
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
// Taint sink: state change without anti-forgery check
update_user_email($_POST['email']);
echo "Email updated successfully.";
}
Secure Code Pattern
// ✅ SECURE: Anti-forgery token validation
session_start();
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
if (!hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'])) {
die("CSRF token validation failed.");
}
// Sanitized state change
update_user_email($_POST['email']);
echo "Email updated successfully.";
}
How Precogs Detects This
Precogs API Security Engine comprehensively audits all state-changing web endpoints to ensure strict anti-forgery token validation.\n